Question

A `40kg` shell is flying at a speed of `72km//h` It explodes into two pieces One piece of mass `15kg` just stops . What is the speed of the other ?

Answer 1

Correct Answer - `32m//s` .
Here, `m = 40kg, upsilon = 72 km//h = 20m//s`
`m_(1) =15kg upsilon_(1) = 0, m_(2) = 40 - 15 =25 kg`
`upsilon_(2) = ?`
As `m_(1) upsilon_(1) + m_(2) upsillon_(2) = m upsilon`
`0 + 25 upsilon_(2) = 40 xx 20, upsilon_(2) = (800)/(25) = 32m//s` .